Some RISC OS Systems to put some more strain on the harddiscs than other computer types due to the fact that they are placed to ensure a minimum cooling of the disc despite cooling being important for the drives.
In the Risc PC the disc is in the most weird spot since it is where the fan from the power supply does not really ventilate, it is not connected to some bigger metal parts which could spread the heat and it is below other parts with no space below so that there is not even a reasonable air flow due to the disc heating the air. In my ex-Risc PC I simply moved the disc to a podule slot and added a silent fan to ensure that the disc is run in the operating temperatures it was designed for and ever since I did that all my harddisc access problems vanished.
In the classic IYONIX pc the hard disc placement is not much better since it is again in a place where there is not air flow due to the fan of the power supply and it is mounted directly below the floppy disc drive to ensure that you have no reasonable air flow due to the disc heating the air. OK, the harddisc mounting case is metal but so thin that as heat spreader it is close to a joke. The result was (as with my Risc PC) that after longer working sessions especially in summer I got the odd disc error, easily solved by shutdown, wait a while, reboot and usually DiscKnight was happy with the disc. So I mounted the harddisc vertically near the rear of the box where the air openings are and added a hard disc cooler which I run with 5 Volts so that it is very silent. Ever since I had no more harddisc errors.
Take A9home: Again the harddisc has a hard time since the case is completely closed and thus no air flow at all. Initally I assumed that the disc would be tightly screwed to the metal case so that that works as a heat spreader but by now we all know that that is not the case. Due to that I'm not surprised that the odd user already had hard disc issues with A9home.
Due to this doing backups is absolutely recommended for standard Risc PC, IYONIX pc classic and A9home since that are desingns with kind of a built-in guarantee for a comaratively short harddisc life span - I don't know about the other models ... except VirtualRPC which does not have this issue